Method for manufacturing positive electrode active material for nonaqueous electrolyte secondary battery

A positive electrode active material and non-aqueous electrolyte technology, applied in the field of non-aqueous electrolyte secondary batteries, can solve the problems of increased cost and low discharge capacity, and achieve the effects of large initial discharge capacity and excellent charge-discharge cycle characteristics.

Inactive Publication Date: 2012-04-18
SANYO ELECTRIC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is a problem that the lithiated spinel-structured manganese oxide synthesized by this method is different from orthorhombic LiMnO 2 The discharge capacity of the mixture is as low as about 160mAh / g after 10 cycles
However, in this method, since it is synthesized by hydrothermal treatment, there is a problem that the cost increases compared with the solid-phase method.
[0009] In addition, in Patent Document 3, although LiMn having a monoclinic crystal structure is synthesized by a solid-phase method, 1-y Al y o 2 (0.06≤y<0.25), but due to the addition of electrochemically inert Al, there is a problem that the initial discharge capacity is as low as about 140mAh / g

Method used

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  • Method for manufacturing positive electrode active material for nonaqueous electrolyte secondary battery
  • Method for manufacturing positive electrode active material for nonaqueous electrolyte secondary battery
  • Method for manufacturing positive electrode active material for nonaqueous electrolyte secondary battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0070] Production of positive electrode active material

[0071] γ-MnO 2 (KISHIDA CHEMICAL Co., Ltd., grade 1, purity 90%) and LiOH (KISHIDA CHEMICAL Co., Ltd., special grade, purity 98%) were mixed at a molar ratio (Li:Mn) of 1:1, and further Solid carbon (Ketjen Black) was mixed as a reducing agent in this mixture at a molar ratio (Mn:C) of 4:1. In γ-MnO 2 Acetone was added to the mixture of LiOH, Ketjen Black, and the mixture was stirred and mixed with a ball mill at a speed of 200 rpm for 1 hour.

[0072] The obtained mixture was taken out, dried, and baked at 450° C. in an argon (Ar) gas stream.

[0073] XRD measurement was performed on the powder obtained by firing to identify the structure of the main component. Since the peak of the main component coincides with PDF#87-1255, it is known to have a structure represented by the space group C2 / m. Therefore, the obtained powder was identified as LiMnO 2 represents and has a crystal structure of space group C2 / m lith...

Embodiment 2～7

[0084] A positive electrode active material was produced in the same manner as in Example 1 except that the calcination temperature, Li / Mn molar ratio, and C / Mn molar ratio were set to the values ​​shown in Table 1.

[0085] The main components of the obtained positive electrode active material were identified in the same manner as in Example 1. In addition, a positive electrode was produced in the same manner as in Example 1 using the obtained positive electrode active material, a test battery was produced using the produced positive electrode, and a charge-discharge test was performed in the same manner as in Example 1.

[0086] Table 1 shows the identification results of the main components by XRD and the initial discharge capacity.

Embodiment 8～13

[0103] A positive electrode active material was produced in the same manner as in Example 1 except that the calcination temperature, Li / Mn molar ratio, and C / Mn molar ratio were set to the values ​​shown in Table 2.

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Abstract

A method for manufacturing a positive electrode active material for a nonaqueous electrolyte secondary battery including the steps of mixing a lithium source and a tetravalent manganese source and reacting the lithium source and the manganese source at a temperature lower than 600 DEG C. while tetravalent manganese is reduced, so as to produce a lithium manganese compound oxide, wherein the positive electrode active material is formed from the lithium manganese compound oxide where the lithium manganese compound oxide is represented by a general formula LixMnO2 (x>=1) and which has a crystal structure of a space group C2 / m.

Description

technical field [0001] The present invention relates to a method for producing a lithium-manganese composite oxide as a positive electrode active material for a nonaqueous electrolyte secondary battery, a positive electrode active material for a nonaqueous electrolyte secondary battery, and a nonaqueous electrolyte secondary battery using the same. Background technique [0002] In the past, it is known that there are devices using LiCoO 2 A non-aqueous electrolyte secondary battery with a positive electrode as a positive electrode active material. However, since Co is a scarce and expensive resource, LiCoO 2 When used as a positive electrode active material, the production cost of a nonaqueous electrolyte secondary battery becomes high. Therefore, research is prevailing to develop alternative LiCoO 2 new positive electrode active material. [0003] In particular, it is expected that one of the cheapest transition metals, that is, manganese oxide, will be used in positive...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): H01M4/505H01M10/052
CPCH01M4/505Y02E60/122H01M4/04Y02E60/10
Inventor堂上和范虞有为
OwnerSANYO ELECTRIC CO LTD